Chapter 4: Physical Development: Body, Brain, and Perception

1
Chapter 4 Physical Development Body, Brain, and
Perception

• Physical Growth and the Development of Motor
  Coordination

By Kati Tumaneng (for Drs. Cook Cook)
2
Physical Growth

• Average newborn weighs 7.5 lbs. and is 20 inches
  long.
• Birth weight doubles by 5 months.
• Girls reach 50 of adult weight by age 9, boys by
  age 11.
• Length increases by 50 in first year.
• By age 2 have attained more than 50 of adult
  height.
• Growth hormone production peaks during sleep.
• Clinical Growth Charts http//www.cdc.gov/nchs/ab
  out/major/nhanes/growthcharts/clinical_charts.htm

3
Physical Growth

• Adolescent Growth Spurt Increase in growth
  associated with the onset of puberty.
• Sparked by sex hormones
• Occurs at age 12 for females, age 14 for males
• Girls briefly taller on average than males around
  ages 11-14.
• Spurt lasts longer for males who average 5 inches
  taller than females by age 18.
• Puberty (AAP)
• http//www.aap.org/family/puberty.htm

4
Average Body Weight for Girls and Boys ages 2-20
years
5
Height Curves for Girls and Boys
6
Sexual Maturation

• Sex hormones stimulate growth in the reproductive
  system
• Androgens Released in greater concentration in
  males.
• Estrogens Released in greater concentration by
  females.
• As with growth, sexual maturation earlier for
  girls with menarche (first menstrual period)
  occurring between ages 12 and 13. Most boys enter
  puberty 1-2 years later.
• Over last 100 years, children larger and maturing
  faster the secular trend.

7
Sexual Maturation

• Psychological Effects
• For many adolescents, it is a confusing and
  awkward time.
• Changing body image.
• Girls tend to become less satisfied with body.
  Boys tend to become more satisfied.
• Early-maturing girls and late-maturing boys often
  most dissatisfied.

8
Reflexes The Infants First Coordinated Movements

• Reflexes Involuntary movements that are
  elicited by environmental stimuli.
• Purposes vary nourishment, exercise, protection
• Three classes
• Primitive Help the infant find nourishment or
  served protective functions during earlier
  periods of evolution.
• Postural Help infants keep their heads upright,
  maintain balance, and roll their heads in the
  direction of their body lean.
• Locomotor Mimic Locomotor movements such as
  crawling, walking, and swimming.
• Begin to disappear as early as 4 months as brain
  develops more voluntary control.

9
Voluntary Movements The Motor Milestones

• Cephalocaudal pattern Head-to-toe
• 1 month hold head up
• 3 months roll over
• 6 months sit upright without support
• 7 months crawling stand by holding onto
  support
• 12 months first steps

10
Voluntary Movements The Motor Milestones
11
Voluntary Movements The Motor Milestones

• Proximodistal Nearer-to-farther (from bodys
  center)
• 4-5 months voluntary control over upper arm
  palmer grasp, wrap all 4 fingers and thumb around
  an object
• 10 months more advanced pincer grasp, using
  thumb opposite forefinger
• 15 months can hold a pen make scribbles using
  large muscles in upper arms
• 2-3 years tripod grasp for holding pen
• 4 years fine-motor coordination print a few
  letters
• 5 years more control over printing write name
• 6 years print whole alphabet and numbers to 10

12
Voluntary Movements The Motor Milestones
13
Voluntary Movements The Motor Milestones

• Trends mirror brain development
• Dynamic systems theory describes motor
  development in terms of complex interacting
  forces
• Neurological development, parental encouragement,
  cognitive systems, opportunity to exercise,
  cultural factors all work together to propel
  development

14
Nutrition and Eating-Related Problems

• Healthy diet includes proteins, carbohydrates,
  fats, and minerals and vitamins.
• Malnutrition Nutritional deficiency caused by
  inadequate intake of calories, protein, vitamins,
  or minerals.
• 12 million Americans lived in families that
  sometimes or often did not have food or money
  to buy food.
• In developing countries, 230 million children
  under 5 are seriously malnourished.
• WHO Database of Malnutrition
• http//www.who.int/nutgrowthdb/en/

15
Nutrition and Eating-Related Problems
16
Nutrition and Eating-Related Problems

• Short- and long-term effects of malnutrition
• Stunted growth
• Reduced muscle and body mass in adolescents
• Female adolescents show delayed menarche
• Impede fetal growth
• Babies born with low birth weight, smaller brain
  size, and impaired mental and motor behavior
• Lowered intelligence
• Perform less well in school
• Into adulthood, suffer physical and intellectual
  deficits that limit ability to earn a good wage

17
Nutrition and Eating-Related Problems

• Obesity Most frequent nutritional problem in US
• Percentage of US obese children and adolescents
  tripled from 1960s to 2000
• 64 adults over 20 are obese
• African American and Hispanic children and teens
  higher rates of overweight and obesity than
  Caucasian Americans
• Rely more on fast foods and processed foods
• Less physically active
• Surgeon General Call to Action
  http//www.surgeongeneral.gov/topics/obesity/callt
  oaction/fact_adolescents.htm

18
Nutrition and Eating-Related Problems
19
Nutrition and Eating-Related Problems

• Eating Disorders Pressure to be thin high for
  women and girls. Increasing in males.
• Anorexia Nervosa Distorted body image, intense
  fear of gaining weight, and refusal to maintain a
  healthy weight. 1 out of 100 female adolescents.
• http//www.altrue.net/site/anadweb/
• Bulimia Nervosa Binge eating followed by
  purging, fasting, or excessive exercise. 2-3 out
  of 100 female adolescents.
• http//www.4woman.gov/faq/Easyread/bulnervosa-etr
  .htm
• Both are likely caused by a combination of
  genetic, social, and psychological factors.

20

• Chart on Slide 4 from Cook, J. L., Cook, G.
  (2005). Child development Principles and
  perspectives (1st ed.) (p. 131). Boston Allyn
  and Bacon.
• Chart on Slide 5 from Cook, J. L., Cook, G.
  (2005). Child development Principles and
  perspectives (1st ed.) (p. 132). Boston Allyn
  and Bacon.
• Babies on Slide 10 from Cook, J. L., Cook, G.
  (2005). Child development Principles and
  perspectives (1st ed.) (p. 137). Boston Allyn
  and Bacon.

21

• Babies on Slide 12 from Cook, J. L., Cook, G.
  (2005). Child development Principles and
  perspectives (1st ed.) (p. 139). Boston Allyn
  and Bacon.
• Chart on Slide 15 from Cook, J. L., Cook, G.
  (2005). Child development Principles and
  perspectives (1st ed.) (p. 142). Boston Allyn
  and Bacon.
• Chart on Slide 18 from Cook, J. L., Cook, G.
  (2005). Child development Principles and
  perspectives (1st ed.) (p. 142). Boston Allyn
  and Bacon.
• All other images retrieved from Microsoft
  PowerPoint Clip Art.